<template>
  <div class="header">
      <!-- 折叠按钮 -->
      <div class="collapse-btn" @click="collapseChange">
          <i v-if="collapse" class="el-icon-s-fold"></i>
          <i v-else class="el-icon-s-unfold"></i>
      </div>
      <!-- LOGO -->
      <div class="logo">Gudy证券交易系统</div>
      <!-- 用户信息+下拉菜单 -->
      <div class="header-right">
          <div class="header-user-con">
              <el-dropdown class="user-name" trigger="click" @command="handleCommand">
                  <span class="el-dropdown-link">
                      {{username}}
                      <i class="el-icon-caret-bottom" />
                  </span>
                  <el-dropdown-menu slot="dropdown">
                      <el-dropdown-item command="loginout">退出登录</el-dropdown-item>
                  </el-dropdown-menu>
              </el-dropdown>
          </div>
      </div>
  </div>
</template>

<script>

    import {logout} from '../api/loginApi'
  
    export default {
        name: 'Header',
        data() {
            return {
                collapse : true, //折叠菜单的打开
            }
        }, 
        computed: {
            username() {
                let acc = sessionStorage.getItem("uid");
                return acc ? acc : 'guest';
            }
        },
        methods: {
            //改变折叠菜单的图标状态
            collapseChange() { 
                this.collapse = !this.collapse;
                this.$bus.emit("collapse", this.collapse);//往组件上丢一个collapse消息,表示当前是打开还是关闭
            },
            //下拉菜单事件响应
            handleCommand(command) {
                if(command == 'loginout') {
                    logout();
                }
            }
        }
    }
</script>

<style scoped>
    .header {
        position: relative;
        box-sizing: border-box;
        width: 100%;
        height: 70px;
        font-size: 22px;
        color: #fff;
    }

    .collapse-btn {
        float: left;
        padding: 0 21px;
        cursor: pointer;
        line-height: 70px;
    }

    .header .logo {
        float: left;
        width: 250px;
        line-height: 70px;
    }

    .header-right {
        float: right;
        padding-right: 50px;
    }

    .header-user-con {
        display: flex;
        height: 70px;
        align-items: center;
    }

    .btn-bell .el-icon-bell {
        color: #fff;
    }

    .user-name {
        margin-left: 10px;
    }

    .user-avator {
        margin-left: 20px;
    }

    .user-avator img {
        display: block;
        width: 40px;
        height: 40px;
        border-radius: 50%;
    }

    .el-dropdown-link {
        color: #fff;
        cursor: pointer;
    }

    .el-dropdown-menu__item {
        text-align: center;
    }
</style>
